This invention relates to automatic fluid dispensing systems such as are used in the gasoline pumping installations and at automobile stations. However, it will be readily recognized that the system of the invention can be utilized for dispensing other fluids in other environments.
A typical gasoline dispenser includes a remotely positioned fluid pump, one or two flow control valves, a hose with nozzle for insertion into the vehicle tank with a flow control on the nozzle, and one or more manually operated switches for starting and stopping the system. Fluid flow through the outlet line is measured, the volume of material dispensed is calculated and displayed, the price or monetary amount of the sale of material is calculated and displayed, and the unit price of the material is displayed.
The present invention is directed to automatic fluid dispensers wherein the customer makes an initial deposit, with the dispenser providing payout of change of the customer in the event that the customer does not take all of the fuel initially paid for. The customer may make a deposit by inserting tokens or coins or bills into the dispenser, or by dealing with an attendant who will introduce the deposit data into the system by electrical or mechanical means.
A variety of automatic gasoline dispensers with change making capability are described in the prior art and a number of them have been placed in service. Typical systems are disclosed in the following U.S. Patent Nos. and the art of record therein: 3,550,743; 3,605,973; 3,666,928 and 3,731,777. The first two patents describe improved electromechanical systems and the latter two patents disclose more advanced solid-state systems. The present invention is a digital solid-state electronic dispensing system that is an improvement on the prior art systems providing increased accuracy, performance and reliability.